Lubricants

Lubricants

– substances that have a lubricating effect. They are used for lubrication of friction parts of machines and devices, as well as for metal working with pressure. As lubricants, liquid oils of predominantly petroleum origin, synthetic oils, greases, solid substances (graphite, molybdenum disulphide, polymers with fillers), gaseous substances (air, hydrocarbon vapors, halogenated methane compounds, etc.) and surfactants ( soap, glycerin, etc.). According to the aggregate state, properties and purpose are divided into groups and varieties.

Progress goes forward by leaps and bounds, new mechanisms appear, improved equipment, the features of servicing of which sometimes differ somewhat from care for the usual for the technical specialists of enterprises, but with somewhat obsolete equipment. Erroneous ideas about lubricants, which have been preserved by some technicians for decades, contribute to the appearance of a considerable number of myths and incorrect judgments that do not reflect the features of modern lubrication technologies. Our goal is to dispel the most common myths about industrial lubricants.

All lubricants are for one person.

Lubricants, by and large, perform one function, but there are still differences between them, and considerable. Some are quite obvious (viscosity, color, etc.). Other, not less significant, qualities can not be defined “by eye”, but it is necessary to consider, selecting the necessary lubricant. It should be remembered that each of the hundreds of industrial lubricants contains additives mixed specifically for a particular application. It is the use of an unsuitable lubricant that can cause the failure of the mechanisms, while the use of a lubricant that has the necessary qualities helps to increase the efficiency of the machine and prolong the life of the equipment.

Pennsylvania Oil is the best raw material for the production of lubricants.

This view was quite valid at a time when the process of separating the lubricant base from crude oil was quite complex, and it was from Pennsylvania crude oil that it was possible to produce raw materials having a relatively high corrosion resistance and a high viscosity index. But nowadays many oil companies use technologies that allow to obtain equally qualitative base components for the preparation of lubricants from various types of crude oil (by changing the set of additives).

Oil can not be produced.

The oil oxidizes and can thicken under the influence of operating temperatures above 65 ° C. After a while (the duration of which depends on the quality of the oil and the operating temperature), a film is formed on the equipment – traces of the grease material being stuck. To avoid this, periodically change the oil in the mechanisms (every six months or once a year – depending on the temperature at which the equipment operates).

The main reason for equipment failure is the old oil.

This is not quite true. Most equipment breaks down or when an unsuitable lubricant is used, or if the concentration of contaminants in the lubricant is high (especially dirt and metal particles causing premature wear and breakage of mechanisms).

To properly choose a lubricant, it is enough to have information about its physical characteristics, information about additives is of little importance, you can not pay attention to it.

Lubricants are produced by oil companies according to certain standards, but neither in color nor in ignition temperature and density, it is impossible to determine what advantages or disadvantages this lubricant possesses, what is the intended method of its application, etc.It should be noted that the additives increase the efficiency and extend the service life of the lubricant, due to them the flow temperature decreases and the range of temperatures for maintaining a sufficient viscosity of the lubricant expands. In addition, additives prevent the formation of foam, control the oxidation, prevent the formation of sludge and film, reduce frictional wear (this should be borne in mind by conducting standard tests of equipment, the results of which, due to additives, can be distorted).

The best lubricating properties of viscous oils.

Indeed, it is the viscous oils that can form thick-film lubricating films. However, it should be remembered that, due to some additives (for example, sulfate and metal additives), the lubricating properties of the oils increase without increasing the viscosity.

If the viscosity of the oils is the same for SAE or ISO, then they are interchangeable.

This is not true. It should be remembered that the SAE and ISO numbers can only help to choose a lubricant with a certain viscosity level, they do not imply any other characteristics. For example, a hydraulic oil can not be replaced with engine oil, although SAE uses lubricants of the same viscosity class.

More viscous oils have more insoluble impurities.

In modern lubricants, detergent or dispersant additives contribute to the retention of a significant amount of insoluble impurities in finely dispersed homogeneous particles. These particles are distributed over the volume of the oil in such a way as to minimize the risk of sediment formation or harmful precipitation. As a result, a lubricant with a rather high viscosity level contains a minimum amount of potentially hazardous insoluble impurities.

The acidity of the oil corresponds to the acid number.

It should be remembered that in most oils, due to metallic additives, the acid number is greater than the acidity of the lubricant itself. If the acid number rises during operation, this may indicate that the oil has acquired corrosive properties or that contaminants and non-corrosive wear products have entered the lubricant.

Having studied the ash content, you can get information about the presence of abrasive components in the oil.

This is not quite true. After all, some metal additives can form non-abrasive ash, which, in fact, does not contain any information about the oil itself. To detect abrasive components, the oil must be driven through a thin filter disc (5 micron) and examined with a magnifying glass precipitate. A more detailed quantitative and qualitative analysis of the revealed abrasive components can be carried out using spectrophotometry and only in laboratory conditions.

Information on the content of the coke residue by Conradson (CCR) is extremely important.

Indeed, this test, designed to measure the coke residue in the lubrication of a steam cylinder, was very important at a time when the fully absorbed components were digested (the residue was measured during the tests). But, as oil is not digested during the application of modern lubricants and the cause of the occurrence of carbonaceous deposits is most often the aging (or contamination) of the oil, the CCR test has lost its former significance.

Oils with high specific gravity have low resistance to oxidation.

This is not the case when it comes to modern lubricants, whose stability is enhanced by the use of more advanced technologies in oil refineries and the use of additives that increase the resistance of lubricants to oxidation.

It is possible to receive and transfer oil through the system at a temperature not lower than the pour point.

Not necessary. After all, the pour point (at which the lubricant acquires the maximum viscosity, on the verge of solidification) is determined in the laboratory. During testing, the head that supplies oil is approximately 25% in.This should also be taken into account (after all, in operation mode, it can be higher or lower than the test one).

The oil is intended only for lubrication mechanisms, it does not have other functions.

This is not quite true. In addition to the above function, oil dissipates the heating, prevents the ingress of contaminants into the bearing seals, flushes dirt and wear particles (carries them to the filters of the mechanism).

The more lubrication, the better the mechanism will work.

Wrong opinion. It should be remembered that, for example, applying excessive amounts of grease to seals can destroy them (as a result, contaminants can get into the mechanism), and in the motor bearing can penetrate into the winding and cause combustion of the engine. Bearings from excessive lubrication overheat (as the resistance of the liquid increases) and fail, in addition, heating reduces the period of use of oil, etc.

Hydraulic oil is of the lowest quality.

The oil used for power transmission and lubrication of hydraulic pumps, bearings, cylinders, etc., must be wear-resistant, resistant to oxidation, provide a high level of protection for the pump motor, etc. Consequently, oil for hydraulic systems is a good quality lubricant.

If the oil is fireproof, it will not burn.

Unfortunately, this is not the case – fire-resistant hydraulic oils still burn, but only while there is a fire, and immediately after eliminating the fire, combustion ceases (while the ordinary mineral oil continues to burn until extinguishment after removing the fire). In addition, the ignition of fire-resistant hydraulic oil is much more difficult than oil lubricants.

A good specialist can evaluate the quality of grease to taste, smell, etc.

This opinion was quite true when many types of lubricants were produced for a specific application. Indeed, their consistency (sticky, soft and homogeneous, etc.), the taste and smell could easily be discerned for a specialist. But modern lubricants, created for complex use, are almost all soft, oily, short-fibred, and even an experienced person is not always able to determine by eye how good a lubricant is in front of him. The taste of such materials, as a rule, are disgusting and not harmless to the body, therefore it is highly recommended to apply safer methods for estimating the oils.

The anti-seize agent (EP) in the lubricant is molybdenum disulphide.

It should be remembered that the anti-scoring agent should react with the lubricating surface to form a film. Molybdenum disulphide, which is just a thick grease, does not cause such an effect.

вода Water does not penetrate into the grease with water-repellent properties.

Wrong opinion. After all, only after absorbing water, grease starts to repel it. Grease, which has water-repellent properties, does not lose its consistency, absorbing water. Other lubricants (for example, sodium), which do not have water-repellent properties, become softer during the absorption process. After a while, this lubricant is finally diluted and washed away.

The highest quality grease is characterized by the highest drop point.

No. Greases with high points of dropping can be used at higher temperatures, this indicator does not carry information about the quality of the lubricant.

The manufacturer in the guarantee mechanism necessarily indicates the requirements for the use of lubricant.

Unfortunately, such information is not always included in the guarantee. Therefore, before replacing the grease, you should consult the manufacturer (especially if the warranty period has not yet expired).

Any employee can carry out lubrication work.

This is not true. After all, you should not only observe the schedule of lubrication mechanisms, which is really capable of any employee.It should be noted that an experienced lubricant technician, who knows the mechanisms with which he works, is able to notice the problem at the initial stage on various grounds (overheating, sounds, sudden changes in smell or color), which the amateur will not say anything.

Lubrication is an expensive pleasure.

Maybe, but the cost of downtime or the breakdown of expensive equipment due to unsystematic or careless lubrication practices will be even more expensive.

The total cost of lubrication is almost equal to the cost of lubricants.

Alas, this is not so. The ratio between the cost of lubricants and the cost of their use is approximately 1: 5 (after all, it is necessary to take into account the payment for the work of the technician, controller, transportation, storage, etc.).

You can not save much on lubricants.

With the proper use of lubricants most suitable for these mechanisms and this operating mode, effective maintenance, cleaning or filtering of the lubricant makes it possible to significantly reduce the consumption of oils. The savings in some cases are thousands of dollars (for example, the transition to a premium-class lubricant with a long life-span brought one of the manufacturers of metal structures for a year, a profit of 33,000 dollars).

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